The Study Of Treatment Of Odors Containing H₂S And NH₃ In A Biotrickling Filter

As living standards improve, people are becoming more demanding on the quality of the environment, and more sensitive to stench. The odor from Sulphur compounds and nitrogenous compounds,especially the hydrogen sulfur (H₂S) and the ammonia(NH₃) are extensive and toxic even at low concentrations.They could also damage the health of human being and corrode equipments.In addition, it can be oxidized to SO₂ or NO₂ by oxygen and ozone, resulting in acidic rain and destroy our environment.Therefore, decreasing H₂S and NH₃ concentrations and their odor is in great demand in both environmental and economic aspects.Therefore,purification containing H₂S and NH₃ smell has become the national economy, and the urgent need to address the area of environmental protection issues.Comparing with the chemical methods or physical methods,biological method is simple,cost-effictive,environment friendly with low consumption and without secondary pollution.It become the mainstream research and application methods to the odor treatment.Most studies have investigated the removal of H₂S as single pollutant in biotrickling filter.They focus on the research on the technological parameters set,the choice of the packing materials.There are few reports about the research on the co-treatment of different pollutants in a biotrickling filter,the prevention of plugging due to accumulating biomass,and the research on the bacterias and so on.According to these,the co-treatment of the H₂S and NH₃ is studied in this test,and results of the experiment were achieved as follows:1. The suitable ecological conditions for microbial degradation of the H₂S and NH₃ are:temperature at 25℃, the nutrient sprinkling rate at 8L/h, aeration rate at 0.4m³/h with incoming H₂S concentration at 712.80⁹48.80mg/m³ and NH₃ at 422.20⁷95.40mg/m³, pH at 7.0-8.0, under which, both of the cleaning efficiency could be up to 90 %.2. As the co-treatment of the H₂S and NH₃,the pH value become to 6.5⁸.5.But It has little impact on the dominating bacterias and the cleaning efficiecy.Therefore it can save the operational costs for it needn't to regulate the pH value.3. In the co-treatment of the H₂S and NH₃, the impact on the cleaning efficiecy of the NH₃ with the nutrient sprinkling rate is stonger than the H2S.4. It found that the height of packing affect the cleaning efficiecy.The study shows that with the incoming H₂S concentration at 682.4⁹55.8mg/m³,the cleaning efficiecy in the underlayer of the reactor is up to 50%⁶0%,and in the both of the underlayer and the middlelayer is up to 90%.Therefore,most of the pollutants are removed at the bottom of the biotrickling filter.5. The loss of the press due to the accumulating biomass in the biotrickling filter rises up with the increase in operational time.It rises up fastest at the underlayer,from 63.74Pa to 235.36Pa, then the middlelayer.It has little change at the uplayer.There is not any clugging duo to the accumulation of excess biomass during the operation.6. It was recognized that the main microbes used in the experiment are Thiobacillus, Beggiatoa, and Bacillus and so on.So to sum up,the co-treatment of the H₂S and NH₃ in the biotrickling filter has agood cleaning efficiecy. It provides a available method to solve the pollution issue of odor containing with H2S and NH3.